通過請求和響應頭中增加

Accept-Encoding: gzip

Content-Encodin:gzip

確定客戶端或伺服器端是否支援壓縮

舉例，客戶端傳送請求，服務端壓縮響應資料返給客戶端

1、客戶端請求中增加Accept-Encoding: gzip表示客戶端支援gzip；

2、服務端接收到請求後，將結果通過gzip壓縮後返回給客戶端並在響應頭中增加Content-Encodin:gzip 表示響應資料已被壓縮

3、客戶端接收請求，響應頭中有Content-Encodin:gzip表示資料需解壓處理

客戶端也可以傳送壓縮資料給服務端，通過程式碼將請求資料壓縮即可，規範起見同樣要在請求中加入Content-Encodin:gzip

OkHttp壓縮資料：

    private RequestBody gzip(final RequestBody body) {
        return new RequestBody() {
            @Override
            public MediaType contentType() {
                return body.contentType();
            }

            @Override
            public long contentLength() {
                return -1; // We don't know the compressed length in advance!
            }

            @Override
            public void writeTo(BufferedSink sink) throws IOException {
                BufferedSink gzipSink = Okio.buffer(new GzipSink(sink));
                body.writeTo(gzipSink);
                gzipSink.close();
            }
        };
    }
 

    public RequestBody getGzipRequest(String body) {
        RequestBody request = null;
        try {
            request = RequestBody.create(MediaType.parse("application/octet-stream"),compress(body));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return request;
    }
 

OkHttp解壓（自動響應gzip解壓）：

通過BridgeInterceptor類攔截響應，自動處理gzip解壓

通過GZIPOutputStream、GZIPInputStream壓縮和解壓：

    public static byte[] compress(String str) throws IOException {
        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
            try (GZIPOutputStream gzip = new GZIPOutputStream(out)) {
                gzip.write(str.getBytes(StandardCharsets.UTF_8));
            }
            return out.toByteArray();
            //return out.toString(StandardCharsets.ISO_8859_1);
            // Some single byte encoding
        }
    }

    public static String uncompress(byte[] str) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try (GZIPInputStream gis = new GZIPInputStream(new ByteArrayInputStream(str))) {
            int b;
            while ((b = gis.read()) != -1) {
                baos.write((byte) b);
            }
        }
        return new String(baos.toByteArray(), StandardCharsets.UTF_8);
    }